Aerial ladder and support therefor



Jan. 13, 1970 c. .1. RICKRODE ET AL 3,489,244

AERIAL LADDER AND SUPPORT THEREFOR 4 Sheets-Sheet 1 Filed May 9, 1968 IN VENT ORS emu. J. RICKRODE CHARLES A. MC GOUGH JR. ALFRED T. KING BY ATTORNEY Jan. 13, 1970 c. J. RICKRODE ET AL 3,489,244

AERIAL LADDER AND SUPPORT THEREFOR Filed May 9, 1968 4 Sheets-Sheet 2 INVENTORS CYRIL J.RICKRODE CHARLES A. MC GOUGH 4e ALFRED T. KING /7 7 BY v ATTORNEY Jan. 13, 1970 c. J, RICKRODE ET AL 3,489,

AERIAL LADDER AND SUPPORT THEREFOR Filed May 9, 1968 4 Sheets-Sheet 5 36 INVENTORS 36 FIG 7 CYRIL J. RICKRODE CHARLES A. MC GOUGH ALFRED T. KING w N I ATTORNEY Jan. 13, 1970 Q J RICKRQDE ET AL 3,489,244

AERIAL LADDER AND SUPPORT THEREFOR Filed May 9, 1968 4 Sheets-Sheet 4 36 FIG. 9

INVENTORS CYRIL Jl RICKRODE CHARLES A. MC GOUGH JR- ALFRED T. KING BY ATTORNEY United States Patent AERIAL LADDER AND SUPPORT THEREFOR Cyril J. Rickrode, New Oxford, Charles A. McGough, Jr.,

Hanover, and Alfred T. King, Lansdale, Pa., assignors to Cam Industries, Inc., Hanover, Pa., a corporation of Pennsylvania Filed May 9, 1968, Ser. No. 727,968 Int. Cl. E06c /06 US. Cl. 182-66 20 Claims ABSTRACT OF THE DISCLOSURE An aerial ladder adapted to be mounted upon a service vehicle such as used by a utility company and including a platform supported in substantially elevated position above the bed of said vehicle, a ladder having side members pivotally connected at one end to means carried by said platform, vertical frame means comprising substantially parallel side frame members preferably comprising inverted U-shaped members arranged to be connected at the lower ends thereof to the bed of a vehicle adjacent opposite sides thereof, and horizontal frame means connected to the upper portions of said side frame members to support said platform, coaxial circular means respectively connected to said platform and said horizontal frame means with anti-friction supporting and connecting means therebetween, a hydraulic piston and cylinder unit connected at one end to said ladder adjacent its pivotal connection to said platform and at its other end being connected to the circular member on said platform, and chord-like bracing members extending across said circular member on said platform between the pivotal connection for said hydraulic unit and the pivots for said side members of said ladder so as to brace said circular member against being sprung when hydraulic pressure is exerted by said hydraulic unit against said ladder to raise and lower the same.

BACKGROUND OF THE INVENTION Many forms of aerial ladders are available for connection to the beds of service vehicles and the like. The vast majority of these however are supported by a single pedestal member usually of substantial siZe and crosssectional dimension which is connected rigidly at its base to the bed of a vehicle approximately centrally thereof. Because of such location upon such bed and the normal cross-sectional dimension of such pedestal member, only very limited space remains between the opposite sides of said pedestal and the sides of the vehicle bed as well as fore and aft thereof for the accommodation of tools, cargo and the like.

SUMMARY OF THE INVENTION It is the principal object of the present invention to provide an aerial ladder which may be of a longitudinally extendable nature and capable of being connected pivotally at one end to vertical frame means for raising and lowering of the opposite end of said ladder to substantial heights and also for movement of said ladder at the pivoted end thereof about a substantially vertical axis through 360 of rotation, in opposite rotary directions, said vertical frame means being of such nature that substantially parallel side members are mounted vertically with respect to the bed of a vehicle adjacent opposite sides thereof so as to provide a maximum area of unobstructed cargo space on the bed of the vehicle without impairing the supporting of the ladder by said vertical frame.

Another object of the invention is to provide on the upper portion of said vertical frame means rigid horizontal frame means which are spaced a substantial distance above the bed of the vehicle to support a pair of complementary circular members, one of which is connected rigidly and stationarily to the horizontal frame means While the other is arranged for circular movement about a vertical axis with respect to said stationary circular member, said movable circular member supporting adjacent one side thereof pivot means to which one end of the side members of said aerial ladder are connected and the opposite side of said movable circular member supporting pivot means to which one end of a hydraulic piston and cylinder unit is connected, the opposite end of said unit being connected to said ladder in spaced relationship to the pivot means thereof to effect raising and lowering of the outer end of said ladder, and brace members extend respectively between said pivot means for said hydraulic unit and said pivot means for the side members of the ladder in order that said circular member may not be sprung from its preferred shape during raising and lowering movement of said ladder by said hydraulic unit, whereby said movable circular member may be formed from a relatively inexpensive metal strip at relatively low fabricating cost.

A further object of the invention is to provide an annular groove around the exterior surface of said movable circular member for the reception of anti-friction supporting means carried by said stationary circular member at circumferentially spaced locations thereon, endless flexible drive means extending around the exterior of said stationary circular member and engageable preferably with a series of circumferentially spaced sprocket segments which are fixed to said stationary circular member, and a motor being carried by said platform which is movable With said movable circular member and having a driving sprocket around which said endless flexible driving member extends for purposes of said motor revolving said platform and ladder about the central, vertical axis of said fixed circular member which preferably is substantially central of said vertical frame means.

Details of the invention and the foregoing objects thereof, as well as other objects thereof, are set forth in the following specification and illustrated in the accompanying drawings comprising a part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of an exemplary vehicle upon which an .aerial ladder embodying the principles of the present invention is mounted in accordance with the preferred constructions of the present invention.

FIG. 2 is a top plan view of tthe combination vehicle and aerial ladder arrangement shown in FIG. 1 with portions of the sides thereof being partially removed to accommodate the view to the sheet.

FIG. 3 is a rear elevation of the aerial ladder and supporting frame therefor as shown in FIGS. 1 and 2, and the portion of the vehicle body shown therein being illustrated in phantom in operative relationship with said ladder and supporting frame.

FIG. 4 is a fragmentary plan View illustrating details of the supporting mechanism for the ladder and essentially comprising a top plan view of the mechanism shown in FIG. 3.

FIG. 4a is a vertical sectional view of a detail of the mechanism shown in FIG. 4 as seen on the line 4a-4a thereof.

FIG. 5 is a side elevation of the supporting mechanism shown in FIG. 4 as seen on the line 5--5 at one side thereof.

FIG. 6 is a view similar to FIG. 4 but illustrating in more complete manner, in phantom, the relative size of the preferred platform arrangement associated with the ladder supporting means illustrated in the preceding figures.

FIG. 7 is a fragmentary, somewhat diagrammatic side :levation of the mechanism shown in FIG. 6, one position )f the ladder supporting means being shown in full lines ind another, elevated position thereof being illustrated in ahantom.

FIG. 8 is a fragmentary, vertical elevation showing de- :ails of the supporting mechanism for the rotatable circuar member by which the ladder is supported and the means for rotating the same about the vertical axis of ;aid circular member, essentially as shown on the irreguiar line 8-8 of FIG. 9.

FIG. 9 is a fragmentary, plan view illustrating the essential elements of the power-operated means by which :he ladder supporting member is rotated about a vertical axis with respect to the supporting frame therefor, as seen essentially on the line 99 of FIG. 8.

FIG. 10 is a fragmentary vertical elevation of exemglary pivot means between certain station and movable neans of the ladder supporting mechanism to control the movement thereof about said vertical axis.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2 in particular, it will be seen that an exemplary service vehicle 10 is illustrated having a conventional bed 12 at the usual level on said vehicle. Such bed usually comprises a horizontal steel deck or the like and, quite frequently, a pair of side boxes or supply :abinets 14 are provided for the storage of tools and the like. By referring to FIG. 3 however, it will be seen that a substantial amount of available space for the placement of cargo of various kinds is provided between the cabinets or boxes 14 and this space extends for the full length of the bed 12 as can be visualized from FIGS. 1 and 2.

Currently available aerial ladders of the type which are supported by the beds of vehicles generally employ a central pedestal, usually of substantial transverse dimensions, which is affixed substantially centrally to the bed of the vehicle, whereby the most desirable cargo area of the vehicle is monopolized by the pedestal. In contrast to this, the present invention provides a supporting frame which is illustrated and described as vertical frame means 16. Preferably, said frame means comprises a pair of similar, parallel inverted U-shaped side frame members 18. These very conveniently may be formed from industrially available tubular stock such as pipe of appropriate diameter. One commercial form of such frame structure which has been found highly satisfactory has been formed from tubular stock approximately 3 inches in diameter but such dimension is not to be regarded as restrictive. Attaching plates 20 are secured, such as by welding, to the lower ends of the legs of the inverted U-shaped members 18 so that the same might be effectively bolted or otherwise affixed to the upper surface of the bed 12 of the vehicle 10.

Particularly from FIG. 3, it will be seen that the side members 18 are disposed as far apart transversely as is readily possible in view of the width limitations of the bed 12 of the vehicle. Such vertical frame means also include upper, horizontal frame means 22 which are horizontal and preferably parallel with respect to the bed 12 of the vehicle. In preferred construction, the upper frame means 22 preferably comprises a pair of similar parallel members formed from the same type of stock as the side members 18.

When the ends of the members 22 are suitably shaped to be complementary to the exterior surface of the side members 18, they may be rigidly connected thereto, such as by welding, and thereby constitute a very rigid vertical frame comprising the side members 18 and the horizontal upper frame means 22. No additional bracing means is required and it will thus be seen, particularly from FIGS. 1 and 3, that a very substantial amount of cargo space is made available between the side members 18 and below the upper frame means 22, without obstruction of any kind and in no way interferring with the operation of the aerial ladder 24, as will be seen from the following description.

In addition to the vertical frame means 16, the present invention also preferably includes a sturdy ladder rest 26 which, like the side members 18 of frame means 16 may be formed from industrial tubular stock such as pipe. A pair of said members, as seen from FIG. 2, are formed so as to be provided with attaching plates 28 which are arranged to be secured by bolts or otherwise to the bed 12 of the vehicle. Slanting braces 30, formed from pipe or the like, are connected at the upper ends thereof, by welding or otherwise, to the ladder rest members 26 and extend downwardly and rearwardly therefrom, the lower ends being also connected to the bed 12 of the vehicle such as by bolts extending through attaching plates or the like. A horizontal supporting member 32 is fixed to and extends between the forward ends of the horizontal upper portions of the ladder rests 26 and when the aerial ladder 24 is in rest position, such as while being transported to a job site, the same rests upon the supporting member 32.

Referring to FIGS. 4, 6, 8 and 9, it will be seen that the supporting structure for the aerial ladder also comprises a stationary circular frame member 34 which, in cross-section, as seen particularly in FIG. 8, may be formed from a heavy gauge strip of steel or the like and formed into ta circular configuration, the ends thereof preferably being connected such as by welding to form a unitary, integral member. At circumferentially spaced locations around the exterior surface of the frame member 34, a plurality of supporting angular brackets 36 are connected thereto in any appropriate manner such as by welding or the like. One ear of each of the brackets is disposed in a common plane with all of the other corresponding ears of the other brackets. Accordingly, said other cars of all of said brackets are positioned to engage horizontally spaced upper surface portions of the upper frame members 22, to which said ears are connected by providing suitable holes therethrough for the reception of bolts 38, see FIG. 4, by which the circular frame member 34 is fixedly and stationarily connected to the vertical frame means 16.

A ladder support member 40 comprising a circular supporting band is mounted coaxially and concentrically within the stationary circular frame member 34 as is best illustrated in detail in FIG. 8. As also may be seen from FIG. 8, the member 40 preferably is formed simply and inexpensively from a strip of steel or the like of appropriate uniform gauge and width. After shaping the same into circular configuration, the ends are integrally secured such as by welding. The outer diameter of the member 40, as shown in FIG. 8, is sufliciently less than the inner diameter of member 34 that a pair of vertically spaced circular flanges 42 and 44 may be formed thereon, respectively adjacent the upper and lower edges thereof, and are integrally secured thereto by weldingor the like.

Such arrangement provides an annular groove 46 on the exterior surface of the member 40, between said circular flanges 42 and 44 for the reception of a plurality of anti-friction supporting members 48 which, for example, comprise rollers mounted on supporting shafts 50 which extend through appropriate holes in the stationary frame member 34 which are secured in operative position by nuts 52. Any suitable number of the anti-friction supporting members 48 may be provided, such as 6 or 8 depending upon the diameter of the members 34 and 40.

The selected number of anti-friction supporting members 48 preferably are spaced even distances circumferentially around the members 34 and 40. In view of the fact that the anti-friction rollers comprising the supporting members 48 are preferably relatively closely confined within the annular groove 46 between the circular flanges 42 and 44, it will be seen that the supporting members 48 will resist both upward and downward canting movement imposed thereon by the ladder support member 40, depending upon the angle and direction at which the ladder 24 is extended in operative position with respect to the vertical frame means 16.

The circular supporting band 40 comprising the ladder support member is a highly essential feature of the present invention. The formation thereof from strip metal stock, for example, for concentric rotary movement in the stationary circular frame member 34, is made possible only because of certain bracing structure, the details of which are described hereinafter. Said member 40 serves several key functions, specifically in regard to pivotally supporting one end of each of the side members of the ladder 24 and also by contributing measurably to the hydraulic power means by which the ladder is raised and lowered with respect to the pivotal support thereof, details of which are as follows.

Fixedly secured to the inner surface of circular supporting band 40, and projecting radially thereinto at a predetermined location, is an ear 54 which is best shown in FIGS. 4 and 4a. Adjacent the opposite side of the circulating supporting band 40 is a pair of circumferentially spaced brackets 56 which are welded or otherwise affixed to the inner surface of band 40. The brackets 56 are somewhat of an irregular shape as can be seen from FIG. 4a and attached to the upper end of each of the brackets is one end portion of a pair of brace members 58 and 60. Said members may be formed from suitable strip metal and a pivot hole 62 is formed in the end of each which is secured to the bracket 56 as best seen from FIGS. 4a and 5.

The opposite ends of the brace members 58 and 60 are complementary to the inner surface of the circular supporting band 40 and are secured thereto in slightly circumferentially spaced positions with respect to opposite sides of the car 54, as best shown in FIG. 4. Said ends of the brace members 58 and '60 preferably are secured by welding or otherwise to the inner surface of the circular supporting band 40, whereby it will be seen especially from FIG. 4 that the brace members 58 and 60 extend chord-like across the circular supporting band 40, substantially between opposite sides thereof and in V-shaped plan configuration to each other. The operative positions of the outermost ends of members 58 and 60 which contain the pivot holes 62 are further insured by provision of a transverse bracing strut 64 between the outer end portions thereof as shown in FIG. 4, the ends of the strut being secured to the members 58 and 60 by welding or the like.

The outer ends of the brace members 58 and 60 which contain the pivot holes 62 comprise ears through which pivot bolts 66 extend. Said bolts also extend through appropriate pivot holes in preferably sheet-metal pivot plate members 68 and 70. Particularly as seen from FIGS. 1, 5 and 7, said plates are generally triangular in shape and the normally horizontal dimension is substantially greater than the normally vertical dimension with reference to FIG. 1 for example. The uppermost elongated portion of each of said plates respectively are fixed by suitable bolts or otherwise to the adjacent end portions of the side members of the aerial ladder 24 and particularly the larger section thereof in circumstances where, as shown in FIGS. 1 and 2, there is an additional extensible, smaller ladder section 72 arranged for longitudinal projection and retraction relative to the main section 24. Such actuation may be performed conveniently by a hand wheel 74 which operates appropriate conventional Windlass means which includes suitable ropes and the like.

The lowermost corners of the plates 68 and 70, as viewed in FIGS. 1, 5 and 7, for example, are provided with bearing or pivot holes through which the pivot bolts 66 extend for connection of the plates 68 and 70 respectively to the outer pivot ears of brace members 58 and which are integrally connected to the circular supporting band 40 for pivotal movement therewith about the vertical central axis of said band. Such latter pivotal movement is relative to the stationary frame member 34.

The shape of the pivot plate members 68 and 70, and especially the disposition of the hearing or pivot holes in the lowermost corners thereof, offsets the same laterally downward, for example, from the longitudinal axes of the opposite sides of the ladder 24, as clearly shown in FIG. 1 for example. This is for the purpose of effectively employing a powerful and preferably relatively short hydraulic unit 76 for purposes of raising and lowering the outer end of ladder 24 with respect to the pivot bolts 66. Though unit 76 is shown as a ram, it may be a piston and cylinder unit, if desired, and is so referred to herein but without restriction thereto. Details of the connections and functioning of the hydraulic unit 76 are as follows.

Especially from FIGS. 1, 5 and 7, it will be seen that the pivot plate members 68 and 70 have bearings 78 formed therein in locations inward from all the sides and corners of said triangular pivot plate members, the position of the bearings 78 being selected so as to effect a maximum amount of elevating and lowering movement of the ladder 24 with respect to the pivot bolts 66 for a minimum amount of axial movement of the piston of the hydraulic unit 76 relative to the cylinder thereof. One end of the cylinder of the unit 76 is provided with a clevis 80 having a pair of ears respectively disposed on opposite sides of the ear 54, as shown in FIGS. 4 and 6. All of said ears have axially aligned pivot holes therein for the reception of a pivot pin 82. l

The opposite end of the hydraulic unit 76 comprises the outer end 84 of the reciprocable member of hydraulic unit 76. A very simple expedient for connecting end 84 of unit 76 to the ladder pivot plate members 68 and 70 is by providing a cross-head 86 which preferably is T-shaped in cross-section and may be fabricated from plate stock members welded together. The opposite ends thereof are provided with pintles 88 which are respectively received within the bearings 78 supported by the pivot plate members 68 and 70. The outer face, for example, of the outer end 84 of the piston rod preferably abuts the adjacent surface of the cross-head 86 which is parallel thereto and comprises a so-called head strip of the T-shape of the cross-head. A plurality of connecting bolts 90, see FIG. 4, may be threaded into appropriate holes extending inward from said outer face of said outer end 84 of the piston rod.

When hydraulic fluid from a suitable source, not shown, is conducted through flexible conduits or the like, not shown, against the active head of the piston within the cylinder unit 76, the piston rod 84 is projected and causes the pivot plate members 68 and 70, and the ladder connected thereto, to move counter-clockwise, as viewed in FIG. 7 for example, between the full line, rest position shown therein and the exemplary maximum elevated position shown in phantom in said figure. Lowering movement of the ladder is effected by releasing said pressure from the cylinder 76, through appropriate valve means, not shown, and thereby causes the ladder to resume its position of rest as shown, for example, in FIG. 1.

It readily can be visualized especially from certain of the side elevational views and particularly FIGS. 5 and 7, that when hydraulic pressure is applied to the cylinder of the elevating movement of the ladder, when the pintles of the hydraulic unit 76, especially at the commencement 88 are closer to being disposed within a straight line between the pivot bolt 66 and pivot pin 82, very substantial forces are developed between the opposite side portions of the circular supporting band 40 to which one end of the hydraulic unit 76 and the pivot bearings of the pivot plate members 68 and 70 respectively are pivotally connected. However, in view of the provision of the brace members 58 and 60, which are of adequate strength, no noticeable of detrimental displacement or springing of the circular supporting band from its substantially perfectly circular shape occurs.

Another effective expedient of the present invention which makes it possible to employ the sheet metal type pivot plate members 68 and 70 of substantial length and reasonable height, as distinguished from utilizing some sort of more expensive casting or the like for example, is the provision of very simple bracing means extendlng between said plates in the form of a pair of bracing rods 92, best shown in FIG. 3, which are adjacent the rearmost end of said plate members 68 and 70. Said aracing rods may be formed from conventional rod stock of suitable diameter and the opposite ends are threaded to extend through suitable holes in said plate members. The rods are arranged in crossed relationship to form an X-shaped configuration and appropriate locking nuts 94 are secured to the threaded ends of the bracing rods 92. Said' nuts may be tightened upon the ends of brace rods 92 adequately to effect firm bracing, and thereby permit no swaying or skewing of the plate members 68 and 70 from their normal parallel relationship relative to each other or the side members of the ladder to which they are attached.

Plate members 68 and 70 are maintained against movement toward each other when tightening the nuts upon the brace members 92 in view of the connection of the lower end of the plate members to the pivot ears on the outer ends of brace members 58 and 60 and the spacing of said plates thereby, and the disposition of one end of the main ladder section 24 between the upper edges of plate members 68 and 70, preferably along the full extent of the relatively long, upper edges )f said plate members, which prevents movement of said plates toward each other.

For purposes of facilitating the mounting of the ladder 24 by a mechanic to ascend the same, such as when the .adder is projected into operative position, the ladder sup- Jorting means 40, which comprises the circular supportlng band, also supports a deck plate 96 of suitable size and material such as conventional metal decking. A fragnentary portion of the deck plate 9'6 is shown in FIG. 3 and a preferred shape outline thereof is shown in phan- :om in FIG. 6. Said deck plate also preferably is provided with a central opening 98 of irregular configuration complementary to the outline of and accommodating the )race members 58 and 60 as well as the hydraulic cylinler unit 76 as clearly shown in FIG. 6. Referring to FIG. 8, it will be seen that the deck plate 96 may be secured appropriately to circular supporting band 40 by a pluiality of circumferentially spaced brackets 100 of a suitible right-angled nature. One leg of each bracket may be ixed by welding or the like to the inner surface of the iupporting band 40, and the deck plate rests against the Jther horizontal leg of each bracket and is fixed thereby bolts 102, or the like.

In addition to providing a suitable supporting surface For a mechanic incident to mounting the ladder 24 for work in a projected position of said ladder, the deck plate 96 also provides a convenient supporting means for 1 gear reduction unit 104 having a base 106 connected to :he upper surface of deck plate 96 for example, such as ;hown in FIG. 8. Suitable support means 108 extends be- :ween the gear reduction unit 104 and a suitable source )f power such as an electric motor 110.

The drive shaft 112 of the gear reduction unit 4 proects downwardly therefrom for purposes of supporting a lriving sheave 114 which, for example, preferably com arises a double sprocket gear. To enable the driving sheave [14 to cause pivotal movement of the ladder support nember 40, the deck plate 96, and the ladder carried by he member 40 about a vertical axis which is substantialvy central of the member 40, a simple expedient in the Form of a plurality of sprocket segments 116, preferably at least three thereof, are disposed in circumferentially spaced positions. equadistant from each other as shown ;omewhat in diagrammatic manner in FIG. 9. As seen in IG. 8, sprocket segments 116 may be recessed into appropriate openings formed in the stationary circular frame member 34 adjacent the upper edge thereof, for example, and appropriately secured therein by any suitable means such as bolts or pins, not shown. The segments 116 are of the double type which have a pair of parallel arcuate row of sprocket teeth spaced vertically in similar relationship to the vertical spacing of the pair of sprockets on the driving sheave 114.

A pair of endless, flexible driving members 118 extend peripherally around a portion of the sprocket gears of the driving sheave 114 and the outer peripheral surface of the stationary circular frame member 34, engaging the teeth of the spaced sprocket segments thereon. Due to the provision of at least three of such sprocket segments, it readily will be seen from FIG. 9 that in any rotary position of the ladder support member 40, deck plate 96, and power means carried thereby with respect to stationary member 34, the flexible driving member 118 will never engage less than two of said sprocket segments 116. This will be fully adequate to insure effective engagement between the links of the sprocket chains 118 for example and the teeth of the sprocket gears on driving sheave 114 and the teeth on sprocket segments 116. It will be understood that the driving motor will receive power from any suitable source, not shown, and such power will be controlled by an appropriate switch of conventional type, not shown.

In view of the fact that there preferably is suitable but limited clearance between the concentric stationary circular frame member 34 and the rotatable circular supporting band 40 comprising the ladder support member, which clearance can be seen particularly in FIG. 8, it is preferred that a suitable means be provided to control the relative pivotal movement between these two concentric members so they will always be substantially coaxial. Accordingly, an effective, yet simple means for accomplishing this comprises a diametrically extending plate 120 which is fixed at its ends, by Welding or the like, to opposed interior surfaces of the stationary frame member 34 as shown in FIGS. 8 and 9. A similar diametrically extending plate 122 is connected, such as by welding, at its opposite ends to opposed inner surface portions of circular supporting band 40, as shown particularly in FIGS. 6, 8 and 10.

As shown in FIG. 10, intermediately of the ends of the diametrically extending plates 120' and 122, axially aligned, vertically extending pivot holes are formed for the reception of a preferably anti-friction type pivot member 124 which is shown in exemplary manner. Said pivot member therefore maintains said circular members 34 and 40 substantially perfectly concentric with respect to the same about a common vertical axis, whereby during any relative position of the circular members with respect to e'ach other incident to positioning the ladder where desired, there will be no crowding or imposition of undue frictional forces on the pivotal supporting means for the movable, circular supporting band 40, especially in relation to the anti-friction supporting members 48 disposed in the exterior groove 46 of said supporting band 40.

From the foregoing, it will be seen that the present invention provides a relatively simple yet highly effective means for pivotally supporting one end of a service ladder for pivotal raising and lowering movements of the outer end thereof with respect to a rugged but simple supporting mechanism provided for rotation of the pivoted end of said ladder about a substantially vertical axis by power means. Further, all of the supporting mechanism for the pivoted end of the ladder is disposed in vertically spaced relationship above the bed of a service truck by which the ladder is carried, and vertical supporting frame means include side members respectively positioned adjacent opposite sides of the bed of such vehicle, whereby extensive loading or cargo space is provided between said side members and beneath the ladder supporting mechanism free of any encumbrance from the ladder or its elevating or rotating mechanism, as well as its supporting means.

While the invention has been described and illustrated in its several preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as claimed.

What is claimed is:

1. An aerial ladder and support comprising in combination, a circular supporting band, means supporting said band for rotation about its central axis, a ladder having pivot means adjacent one end of the side members thereof, means pivotally interconnecting said pivot means at circumferentially spaced locations to said supporting band adjacent one side thereof, a hydraulic cylinder and piston unit connected pivotally at one end to said ladder adjacent the pivoted end thereof in spaced relation to the axis of said pivot means and the other end of said hydraulic unit being interconnected pivotally to said supporting band at a location diametrically opposite the pivotal connecting means for saidone end of each of the side members of said ladder and operable to pivotally raise and lower the opposite end of saidladder from and to an initial rest position, and bracing means extending across said supporting band substantially between said pivotal interconnections thereon for said side members of said ladder and said one end of said hydraulic unit to prevent said supporting band from springing appreciably from its normal substantially circ'ularshape when said hydraulic unit is operating to raise and lower said ladder and thereby tend to spread apart said pivotal connections for said side members of said ladder and hydraulic unit on said supporting band.

2. The aerial ladder according to claim 1 in which the diameter of said circular supporting band is substantially greater than the width of said ladder between said side members thereof to provide effective bracing for said ladder when supported thereby in elevated position.

3. The aerial ladder according to claim 2 further including a cross-head extending between said side members of said ladder and one end of said hydraulic cylinder and piston unit being connected to said cross-head intermediately of the ends thereof to apply power from said unit to said ladder to effect raising and lowering of the outer end thereof relative to said circular supporting band.

4. The aerial ladder according to claim 2 in which said bracing means comprise a plurality of brace members extending chord-like across said supporting band re spectively between said pivot means for said ends of the side members of said ladder and the opposite side of said circular supporting band to which said one end of said hydraulic cylinder and piston unit is pivotally connected, whereby said brace members extend in angular V-shaped configuration to each other in plan view of said supporting band and prevent any appreciable springing of said circular supporting band from its normal shape.

5. The aerial ladder according to claim 2 in which said pivoted ends of said side members of said ladder comprise similar sheet-like plate members connected in parallel relationship to said side members of said ladder and shaped in side elevation to dispose pivots in said plate members laterally offset from the longitudinal axis of said side members of said ladder, said plates being substantially parallel to each other and transversely spaced apart in accordance with the width of said ladder between the opposite side members thereof, said ladder further including brace members extending between said plate members to maintain the same in parallel relationship during the support of said ladder by said circular supporting band to prevent skewing of said plates from normal positions thereof during various supporting and positioning operations of said ladder by said circular supporting band and hydraulic unit.

6. The aerial ladder according to claim 5 in which said metal plates are substantially triangular in shape and the axes of the supporting pivots therein being adjacent one similar angular corner of each of said triangular plates, thereby disposing said pivot axes in laterally olfset relationship to the edges of said plates which are connected to the side members of said ladder.

7. The aerial ladder according to claim 5 further including a cross-head extending transversely between similar locations in said triangular plate members, said locations being spaced inwardly from the sides and ends of said plates, one end of said hydraulic cylinder and piston unit being connected to said cross-head intermediately of the ends thereof, and the opposite ends of said crosshead being mounted in bearings supported by said plate members at said locations therein.

8. The aerial ladder according to claim 1 in which annular groove means are formed on the exterior of said circular supporting band, anti-friction means extending into said groove at circumferentially spaced locations therearonnd, and support means for said anti-friction means operable to support the same for movement of said circular supporting band about the central axis thereof.

9. The aerial ladder according to claim 8 in which said support means for said anti-friction means comprise a stationary substantially circular frame member coaxial with said supporting band and positioned exteriorally of the same, said stationary frame member having said antifriction means connected thereto at circumferentially spaced locations thereon for said support of said circular supporting band thereby.

10. The aerial ladder according to claim 9 further including motor means interconnected to said circular supporting band for support therewith, and drive means connected between said motor means and said stationary circular frame member operable to effect relative movement between said circular supporting band and said stationary circular frame member.

11. The aerial ladder according to claim 10 further including pivot means provided on a common axis of said coaxial circular supporting band and stationary circular frame member operable to maintain a desired common pivotal operative position of said circular supporting band with respect to said stationary circular frame member.

12. The aerial ladder according to claim 11 further including bracing and supporting members extending substantially diametrically across said circular supporting band and stationary circular frame member for support of said pivot means extending between said band and member.

13. The aerial ladder according to claim 9 in which said drive means comprises an endless flexible member extending around said stationary circular frame member and a rotating driving element on said motor for rotatable movement of said circular supporting band around the central axis thereof with respect to said stationary circular frame member.

14. The aerial ladder according to claim 13 in which said endless member comprises a sprocket chain and said mechanism further including a minimum of three sprocket segments secured to said stationary circular frame member at substantially evenly spaced position around the circumference thereof.

15. An aerial ladder and elevated support means therefor attachable to the bed of a vehicle and comprising in combination, a ladder support member, a ladder having opposite side members pivotally connected at one end to said ladder support member, elevating means carried by said ladder support member and connected to said ladder, power means connected to said elevating means and operable to raise and lower said opposite end of said ladder relative to said ladder support member, vertical frame leans comprising a pair of parallel and transversely paced side frame members mounted within substantially ertical planes in use and the lower ends of said side iembers being arranged to be connected to the bed of a :rvice vehicle adjacent opposite sides thereof, the upperiost portions of said side frame members being substanally parallel to each other and the bed of said vehicle hen said frame members are connected thereto and vercally spaced thereabove a predeterminde distance to proide unobstructed cargo space above said vehicle bed nd between said frame members to the level of said pperrnost portions of said side frame members, and orizontal frame means extending between and rigidly xed at the ends thereof to said uppermost portions of aid side frame members, and means connecting said idder support member to said horizontal frame means form an elevated support for said ladder by said vertial frame means for attachment to the bed of a vehicle.

16. The aerial ladder according to claim 15 further inluding means on said horizontal frame means engaging aid ladder support means for rotataion about an axis ubstant'ially perpendicular to said horizontal frame 163.115 when said ladder is supported by said vertical rame means.

17. Theaerial ladder according to claim 15 in which aid side frame members comprise inverted U-shaped iembers positioned with the ends of the legs thereof )wermost for connection thereof to the bed of a vehicle nd the uppermost portions of said members being suborizontal frame means thereto.

18. The aerial ladder raccording to claim 17 in which said horizontal frame means comprise a plurality of struts extending between and connected at the ends thereof rigidly to said uppermost portions of said U-shaped members and operable to brace said members against lateral swaying.

19. The aerial ladder according to claim 15 further including platform means on said ladder support member and said power means being carried by said platform means and operable to rotate said platform means with said ladder support member and the ladder connected thereto about a vertical axis substantially central of said vertical frame means.

20. The aerial ladder according to claim 19 in which said ladder support member i substantially circular and said horizontal frame means stationarily supports a circular frame member complementary in shape to said circular ladder support member and coaxial therewith, and anti-friction support means extending between said circular members for rotatable support of one member by the other.

References Cited UNITED STATES PATENTS 347,746 8/1886 Stuemplc et a1. 18265 768,700 8 /19.04 Seagrave 18265 1,139,996 5/1915 Predonzan 182-66 2,085,921 7/1937 McElheny 182-66 2,586,531 2/1952 Gordon 18268 REINALDO P. MACHADO, Primary Examiner 

